"Archbishop Emeritus Desmond Tutu has checked into a Cape Town hospital for the treatment of a persistent infection and to undergo tests to discover the underlying cause," his foundation said in a statement on Wednesday.
A photograph of the 81-year-old showed him smiling at his office where he spent the morning before being admitted to the undisclosed hospital.
"He was in good spirits and full of praise for the care he receives from an exceptional team of doctors," said the statement from the Desmond and Leah Tutu Legacy Foundation.
"The non-surgical treatment is expected to take five days."
Officially retired, Tutu is often referred to as South Africa's moral guide due to his outspokenness on wrongdoing at home and in the world.
Just under two weeks ago, he took part in a celebration to mark a recent award, getting up to dance, at the cathedral where he rallied against the apartheid state.
The Nobel Peace Prize laureate was diagnosed with prostate cancer in 1997 and underwent repeated treatments.
-Daily Nation
